From: Jeremy Linton <jeremy.linton@arm.com>
To: Marc Zyngier <maz@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
Thierry Reding <treding@nvidia.com>,
Thomas Gleixner <tglx@linutronix.de>,
Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Ryder Lee <ryder.lee@mediatek.com>,
Marek Vasut <marek.vasut+renesas@gmail.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Michal Simek <michal.simek@xilinx.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Bharat Kumar Gogada <bharatku@xilinx.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-mediatek@lists.infradead.org,
linux-renesas-soc@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v3 13/14] PCI/MSI: Document the various ways of ending up with NO_MSI
Date: Mon, 17 May 2021 23:28:56 -0500 [thread overview]
Message-ID: <b5a5a6d8-6ffc-8c5c-c5b1-fb4f5616069f@arm.com> (raw)
In-Reply-To: <20210330151145.997953-14-maz@kernel.org>
Hi,
On 3/30/21 10:11 AM, Marc Zyngier wrote:
> We have now three ways of ending up with NO_MSI being set.
> Document them.
>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/pci/msi.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index d9c73c173c14..217dc9f0231f 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -871,8 +871,15 @@ static int pci_msi_supported(struct pci_dev *dev, int nvec)
> * Any bridge which does NOT route MSI transactions from its
> * secondary bus to its primary bus must set NO_MSI flag on
> * the secondary pci_bus.
> - * We expect only arch-specific PCI host bus controller driver
> - * or quirks for specific PCI bridges to be setting NO_MSI.
> + *
> + * The NO_MSI flag can either be set directly by:
> + * - arch-specific PCI host bus controller drivers (deprecated)
> + * - quirks for specific PCI bridges
> + *
> + * or indirectly by platform-specific PCI host bridge drivers by
> + * advertising the 'msi_domain' property, which results in
> + * the NO_MSI flag when no MSI domain is found for this bridge
> + * at probe time.
I have an ACPI machine with a gicv2 (no m), and a MSI region that isn't
described by ACPI because its non-standard. In the past this tended to
work because PCIe device drivers would fall back to legacy pci intx
silently. But, with 5.13, it seems this series now triggers the
WARN_ON_ONCE() in arch_setup_msi_irq, because duh, no MSI support.
Everything of course continues to work, it just gets this ugly splat on
bootup telling me basically the machine doesn't support MSIs. So, I
considered a few patches, including just basically setting nomsi if
gicv2 && acpi, or eek a host bridge quirk.
None of these seem great, so how can this be fixed?
Thanks,
> */
> for (bus = dev->bus; bus; bus = bus->parent)
> if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
>
next prev parent reply other threads:[~2021-05-18 4:29 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 15:11 [PATCH v3 00/14] PCI/MSI: Getting rid of msi_controller, and other cleanups Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 01/14] PCI: tegra: Convert to MSI domains Marc Zyngier
2021-04-19 19:19 ` Jon Hunter
2021-04-19 20:02 ` Jon Hunter
[not found] ` <87fszlqria.wl-maz@kernel.org>
2021-04-20 12:45 ` Jon Hunter
2021-03-30 15:11 ` [PATCH v3 02/14] PCI: rcar: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-30 15:28 ` Lorenzo Pieralisi
2021-04-01 10:59 ` Yoshihiro Shimoda
2021-03-30 15:11 ` [PATCH v3 03/14] PCI: rcar: Convert to MSI domains Marc Zyngier
2021-04-01 10:19 ` Lorenzo Pieralisi
2021-04-01 10:38 ` Marc Zyngier
2021-04-01 11:03 ` Lorenzo Pieralisi
2021-03-30 15:11 ` [PATCH v3 04/14] PCI: xilinx: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 05/14] PCI: xilinx: Convert to MSI domains Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 06/14] PCI: hv: Drop msi_controller structure Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 07/14] PCI/MSI: Drop use of msi_controller from core code Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 08/14] PCI/MSI: Kill msi_controller structure Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 09/14] PCI/MSI: Kill default_teardown_msi_irqs() Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 10/14] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 11/14] PCI/MSI: Make pci_host_common_probe() declare its " Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 12/14] PCI: mediatek: Advertise lack of built-in MSI handling Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 13/14] PCI/MSI: Document the various ways of ending up with NO_MSI Marc Zyngier
2021-05-18 4:28 ` Jeremy Linton [this message]
2021-05-18 8:59 ` Marc Zyngier
2021-03-30 15:11 ` [PATCH v3 14/14] PCI: Refactor HT advertising of NO_MSI flag Marc Zyngier
2021-04-01 11:27 ` [PATCH v3 00/14] PCI/MSI: Getting rid of msi_controller, and other cleanups Lorenzo Pieralisi
2021-04-01 12:07 ` Marc Zyngier
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